Delivery devices and methods for heart valve repair

ABSTRACT

Devices, systems and methods facilitate positioning of a cardiac valve annulus treatment device, thus enhancing treatment of the annulus. Methods generally involve advancing an anchor delivery device through vasculature of the patient to a location in the heart for treating the valve annulus, contacting the anchor delivery device with a length of the valve annulus, delivering a plurality of coupled anchors from the anchor delivery device to secure the anchors to the annulus, and drawing the anchors together to circumferentially tighten the valve annulus. Devices generally include an elongate catheter having at least one tensioning member and at least one tensioning actuator for deforming a distal portion of the catheter to help it conform to a valve annulus. The catheter device may be used to navigate a subannular space below a mitral valve to facilitate positioning of an anchor delivery device.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is related to U.S. patent application Ser. No.10/792,681 (Attorney Docket No. 016886-001330US), filed on Mar. 2, 2004,which is a continuation-in-part of U.S. patent application Ser. No.10/741,130 (Attorney Docket No. 016886-001320US), filed on Dec. 19,2003, which is a continuation-in-part of U.S. patent application Ser.Nos. 10/656,797 (Attorney Docket No. 16886-001300US), filed on Sep. 4,2003, and 10/461,043 (Attorney Docket No. 16886-000310US), filed on Jun.13, 2003, the latter of which claims the benefit of U.S. ProvisionalPatent Application Nos. 60/388,935 (Attorney Docket No.016886-000300US), filed on Jun. 13, 2002; 60/429,288 (Attorney DocketNo. 016886-000700US), filed on Nov. 25, 2002; 60/445,890 (AttorneyDocket No. 016886-000800US), filed on Feb. 6, 2003; 60/459,735 (AttorneyDocket No. 16886-000900US), filed on Apr. 1, 2003; and 60/462,502(Attorney Docket No. 016886-001100US), filed on Apr. 10, 2003. The fulldisclosures of all of the above-listed references are herebyincorporated by reference.

The present application is also related to U.S. patent application Ser.Nos. 10/______ (Attorney Docket No. 16886-001340US); 10/______ (AttorneyDocket No. 16886-001350US); 10/______ (Attorney Docket No.16886-001360US); 10/______ (Attorney Docket No. 16886-001380US); and10/______ (Attorney Docket No. 16886-001390US), all of which are filedconcurrently herewith, and all of which are hereby fully incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical devices and methods.More particularly, the invention relates to devices, systems and methodsfor enhancing cardiovascular valve repair, especially the repair ofheart valves such as the mitral and tricuspid valves.

In recent years, many advances have been made to reduce the invasivenessof cardiac surgery. In an attempt to avoid open, stopped-heartprocedures, which may be accompanied by high patient morbidity andmortality, many devices and methods have been developed for operating ona heart through smaller incisions, operating on a beating heart, andeven performing cardiac procedures via transvascular access. Differenttypes of cardiac procedures, such as cardiac ablation techniques fortreating atrial fibrillation, stenting procedures for atherosclerosis,and valve repair procedures for treating conditions such as mitral valveregurgitation have experienced significant technological advances. Inimplementing many minimally invasive cardiac surgery techniques,especially beating-heart techniques, one of the most significantchallenges is positioning a treatment device (or multiple devices) in adesired location in or around the heart for performing the procedure.Another challenge, once a device is positioned, is to effectively deploya given treatment into or on the target cardiac tissue.

One type of cardiac surgery which may benefit from less invasivetechniques is heart valve repair. Traditional treatment of heart valvestenosis or regurgitation, such as mitral or tricuspid regurgitation,typically involves an open-heart surgical procedure to replace or repairthe valve. Valve repair procedures typically involve annuloplasty, a setof techniques designed to restore the valve annulus shape and strengthenthe annulus. Conventional annuloplasty surgery generally requires alarge incision into the thorax of the patient (a thoracotomy), andsometimes a median sternotomy (cutting through the middle of thesternum). These open heart, open chest procedures routinely involveplacing the patient on a cardiopulmonary bypass machine for sustainedperiods so that the patient's heart and lungs can be artificiallystopped during the procedure. Finally, valve repair and replacementprocedures are typically technically challenging and require arelatively large incision through the wall of the heart to access thevalve.

Due to the highly invasive nature of open heart valve repair orreplacement, many patients, such as elderly patients, patients havingrecently undergone other surgical procedures, patients with comorbidmedical conditions, children, late-stage heart failure patients, and thelike, are often considered too high-risk to undergo heart valve surgeryand are relegated to progressive deterioration and cardiac enlargement.Often, such patients have no feasible alternative treatments for theirheart valve conditions.

To obviate this situation, a number of devices and methods for repairingcardiac valves in a less invasive manner have been described. Somedevices provide for heart valve repair through minimally invasiveincisions or intravascularly, while others improve upon open heartsurgical procedures on beating hearts, stopped hearts or both. Asmentioned above, difficulties in performing minimally invasiveintracardiac surgery include positioning a minimally invasive treatmentdevice in a desired location for performing a procedure and effectivelydeploying a given treatment into or on the target cardiac tissue. Inheart valve repair procedures, for example, it is often essential for aphysician to secure one or more treatment devices to valve annulustissue. Annular tissue tends to be more fibrous than surroundingmuscular or valve leaflet tissue, thus providing a more suitablelocation for securing such treatment devices, such as anchors, to treata heart valve. Positioning an anchor deliver device in a desiredlocation adjacent the annular tissue may often be challenging,especially in an intravascular procedure when visualization of thelocation is limited.

Devices and methods that address these difficulties are described inU.S. patent application Ser. Nos. 10/792,681, 10/741,130, 10/656,797,10/461,043, 60/388,935, 60/429,288, 60/445,890, 60/462,502 and60/524,622, which were previously incorporated by reference. Forexample, these references describe devices and methods for exposing,stabilizing and/or performing a procedure on a heart valve annulus, suchas a mitral valve annulus. Many of the devices and methods previouslydescribed by the inventors have been found to be highly effective, butimprovements are still being sought.

Therefore, it would be beneficial to have improved methods, devices andsystems for enhancing heart valve annulus treatment procedures. Ideally,such methods, devices and systems would facilitate positioning of one ormore devices in a left ventricle or elsewhere for performing a procedureon a heart valve annulus, visualizing the annulus and/or the like.Additionally, such methods, devices and systems would ideally beintroduced intravascularly. At least some of these objectives will bemet by the present invention.

2. Description of the Background Art

Published U.S. Application Nos. 2002/0156526, 2003/0220685,2004/0019378, 2004/0003819, 2004/0030382 and 2004/0039442, and U.S. Pat.Nos. 6,629,534 and 6,619,291 describe catheter-based methods forperforming annuloplasty. Published U.S. Application 2002/0042621describes a heart valve annuloplasty system with constrictable plicationbands which are optionally attached to a linkage strip. Published U.S.Application 2002/0087169 describes a remote controlled catheter systemwhich can be used to deliver anchors and a tether for performing anannuloplasty procedure. Other patent publications of interest includeWO01/26586; US2001/0005787; US2001/0014800; US2002/0013621;US2002/0029080; US2002/0035361; US2002/0042621; US2002/0095167; andUS2003/0074012. U.S. patents of interest include U.S. Pat. Nos.4,014,492; 4,042,979; 4,043,504; 4,055,861; 4,700,250; 5,366,479;5,450,860; 5,571,215; 5,674,279; 5,709,695; 5,752,518;5,848,969;5,860,992; 5,904,651; 5,961,539; 5,972,004; 6,165,183;6,197,017; 6,250,308; 6,260,552; 6,283,993; 6,269,819; 6,312,447;6,332,893; and 6,524,338. Publications of interest include De Simone etal. (1993) Am. J. Cardiol. 73:721-722, and Downing et al. (2001) HeartSurgery Forum, Abstract 7025. All of the above cited references arehereby incorporated by reference in the present application.

BRIEF SUMMARY OF THE INVENTION

Devices, systems and methods of the present invention are generally usedto facilitate transvascular, minimally invasive and other “lessinvasive” surgical procedures, by facilitating the delivery of treatmentdevices at a treatment site. “Less invasive,” for the purposes of thisapplication, means any procedure that is less invasive than traditional,large-incision, open surgical procedures. Thus, a less invasiveprocedure may be an open surgical procedure involving one or morerelatively small incisions, a procedure performed via transvascularpercutaneous access, a transvascular procedure via cut-down, alaparoscopic or other endoscopic procedure, or the like. Generally, anyprocedure in which a goal is to minimize or reduce invasiveness to thepatient may be considered less invasive. Furthermore, although the terms“less invasive” and “minimally invasive” may sometimes be usedinterchangeably in this application, neither these nor terms used todescribe a particular subset of surgical or other procedures should beinterpreted to limit the scope of the invention. Generally, devices andmethods of the invention may be used in performing or enhancing anysuitable procedure.

The present application typically describes devices, systems and methodsfor performing heart valve repair procedures, and more specificallyheart valve annuloplasty procedures such as mitral valve annuloplasty totreat mitral regurgitation. Devices and methods of the invention,however, may be used in any suitable procedure, both cardiac andnon-cardiac. For example, they may be used in procedures to repair anyheart valve, to repair an atrial-septal defect, to access and possiblyperform a valve repair or other procedure from (or through) the coronarysinus, to place one or more pacemaker leads, to perform a cardiacablation procedure such as ablating around pulmonary veins to treatatrial fibrillation, and/or the like. In other embodiments, the devicesand methods may be used to enhance a laparoscopic or other endoscopicprocedure on any part of the body, such as the bladder, stomach,gastroesophageal junction, vasculature, gall bladder, or the like.Therefore, although the following description typically focuses onmitral valve and other heart valve repair, such description should notbe interpreted to limit the scope of the invention as defined by theclaims.

That being said, the present invention generally provides devices,systems and methods for enhanced treatment of a cardiac valve annulussuch as a mitral valve annulus. Methods generally involve contacting ananchor delivery device with a length of a valve annulus, delivering aplurality of coupled anchors from the anchor delivery device to securethe anchors to the annulus, and drawing the anchors together tocircumferentially tighten the annulus. One device generally includes anelongate catheter having a housing at or near the distal end forreleasably housing a plurality of coupled anchors. The device may bepositioned such that the housing abuts or is close to valve annulartissue, such as at an intersection of the left ventricular wall and oneor more mitral valve leaflets of the heart. Some embodiments includeself-securing anchors, which may change from undeployed to deployedconfigurations. Anchors may be drawn together to tighten the annulus bycinching a tether slidably coupled with the anchors and/or by aself-deforming member coupled with the anchors. Another device includesa steerable guide catheter for helping position the anchor deliverydevice for treating a valve annulus.

In many cases, methods of the present invention will be performed on abeating heart. Access to the beating heart may be accomplished by anyavailable technique, including intravascular, transthoracic, and thelike. Intravascular access to a heart valve may be achieved using anysuitable route or method. To perform a procedure on a mitral valve, forexample, in one embodiment a catheter may be advanced through a femoralartery, to the aorta, and into the left ventricle of the heart, tocontact a length of the mitral valve. Alternatively, access may begained through the venous system, to a central vein, into the rightatrium of the heart, and across the interatrial septum to the left sideof the heart to contact a length of the mitral valve. In either of thesetwo types of intravascular access, the catheter will often easily beadvanced, once it enters the left side of the heart, into a spacedefined by the left ventricular wall, one or more mitral valve leaflets,and chordae tendineae of the left ventricle. This space provides aconvenient conduit for further advancement of the catheter to a desiredlocation for performing mitral valve repair. In alternative embodiments,a catheter device may access the coronary sinus and a valve proceduremay be performed directly from the sinus. Furthermore, in addition tobeating heart access, methods of the present invention may be used forintravascular stopped heart access as well as stopped heart open chestprocedures. Any suitable intravascular or other access method iscontemplated within the scope of the invention.

In one aspect of the present invention, an anchor device for use withina patient includes: an elongate carrier constructed to be passablethrough a blood vessel and into a heart; a series of tissue-engageableanchors releasably carried by the elongate carrier, the anchorscomprising a distal anchor, a first intermediate anchor and a proximalanchor; a tether serially coupling the anchors to one another, thetether having a distal end secured to the distal anchor or engageablewith the distal anchor when the tether is pulled in a proximaldirection; at least the proximal anchor being slidably coupled to thetether; and a separator positioned along the tether between adjacentones of the anchors to restrict how close the adjacent ones of theanchors can come to one another when the tether is placed in tension.

In some embodiments, the elongate carrier comprises a catheter-typehousing having an open interior. For example, the anchors may in someembodiments be releasably housed within the open interior of thehousing. In some embodiments, the adjacent anchors are the distal andfirst intermediate anchors. In some embodiments, the anchors areself-forming and self-securing. Also in some embodiments, the separatorcomprises a generally tubular member. In such embodiments, the tethermay optionally pass through the generally tubular member.

In some embodiments, the separator has a textured outer surface. Also insome embodiments, the separator is nonporous. Alternatively, theseparator may be porous. In one embodiment, the porous separatorcomprises pores, and the pores are provided by cutouts formed in theseparator. In an alternative embodiment, the separator may be woven orbraided. Such a separator may be rigid in one embodiment. In someembodiments, the separator is effectively axially incompressible. Inalternative embodiments, the separator is axially compressible from afirst length to a second, compressed length. In some embodiments, theaxially compressible separators are joined to one another. In otherembodiments, the separator comprises first and second portions engagingthe tether and a third portion connecting the first and second portions.For example, the third portion may extend to one side of and generallyparallel to the tether.

In one embodiment, the elongate carrier has a longitudinal axis; theanchors are self-forming tissue-engageable anchors; the anchors eachhave a first part and a second part, the second part having atissue-piercing tip; the elongate carrier having openings sized forpassage of the anchors therethrough; the anchors placeable in arelatively straight, undeployed state generally parallel to thelongitudinal axis within the elongate carrier; and the anchors naturallyassuming a curved, tissue-engaging deployed state after passing throughthe opening in the elongate carrier. In some of such embodiments, atleast a portion of the elongate carrier is flexible. Also in someembodiments, the elongate carrier is steerable. In some embodiments, atleast one of the anchors comprises the first part, and at least two ofthe second parts extend from the first part. In such embodiments, thesecond parts may extend in directions generally opposite one anotherwhen in the deployed state. The second parts, in turn, may havegenerally circular or semicircular shapes when in the deployed state.

In some embodiments, the anchors are oriented generally perpendicular tothe longitudinal axis when in the deployed state. In some embodiments,each anchor has a generally circular or semicircular shape when in thedeployed state. In one embodiment, the elongate carrier has adiametrical dimension d and the anchors in the deployed state have adiametrical dimension D, and the ratio of D to d is at least about 3.5.In other embodiments, the ratio of D to d is at least about 4.4, andmore preferably at least about 7, and even more preferably at leastabout 8.8. In some embodiments, the elongate carrier comprises proximaland distal portions, the anchors being carried by the distal portion,the distal portion being releasable from the proximal portions, thedistal portion being pierceable by the anchors.

In another aspect of the present invention, an anchor device for usewithin a patient comprises: an elongate carrier, having a longitudinalaxis, constructed to be passable through a blood vessel and into aheart, at least a portion of the elongate carrier being flexible; aseries of self-forming, tissue-engageable anchors releasably carried bythe elongate carrier, the anchors comprising a distal anchor, a firstintermediate anchor and a proximal anchor; the anchors each having afirst part and at least two second parts extending from the first part,each second part having a tissue-piercing tip; the elongate carrierhaving openings sized for passage of the anchors therethrough; theanchors placeable in a relatively straight, undeployed state generallyparallel to the longitudinal axis within the elongate carrier; theanchors naturally assuming a curved, tissue-engaging deployed stateafter passing through the opening in the elongate carrier; the secondparts having generally circular or semicircular shapes when in thedeployed state; the anchors being oriented generally perpendicular tothe longitudinal axis when in the deployed state; the elongate carrierhaving a diametrical dimension d and the anchors in the deployed statehaving a diametrical dimension D, the ratio of D to d being at least3.5; a tether serially coupling the anchors to one another, the tetherhaving a distal end secured to the distal anchor or engageable with thedistal anchor when the tether is pulled in a proximal direction; atleast the proximal anchor being slidably coupled to the tether; and aseparator positioned along the tether between adjacent ones of theanchors to restrict how close the adjacent ones of the anchors can cometo one another when the tether is placed in tension.

These and other aspects and embodiments are described more fully belowwith reference to the drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a heart with a flexible anchordelivery device being positioned for treatment of a mitral valveannulus, according to one embodiment of the present invention;

FIGS. 2A and 2B are cross-sectional views of a portion of a heart,schematically showing positioning of a flexible device for treatment ofa mitral valve annulus, according to one embodiment of the presentinvention;

FIGS. 2C and 2D are cross-sectional views of a portion of a heart,showing positioning of a flexible anchor delivery device for treatmentof a mitral valve annulus, according to one embodiment of the presentinvention;

FIG. 3 is a perspective view of a distal portion of an anchor deliverydevice, according to one embodiment of the invention;

FIG. 4. is a perspective view of a segment of a distal portion of ananchor delivery device, with anchors in an undeployed shape andposition;

FIG. 5 is a different perspective view of the segment of the deviceshown in FIG. 4;

FIG. 6. is a perspective view of a segment of a distal portion of ananchor delivery device, with anchors in a deployed shape and position;

FIGS. 7A-7E are cross-sectional views of an anchor delivery device,illustrating a method for delivering anchors to valve annulus tissue,according to one embodiment of the invention;

FIGS. 8A and 8B are top-views of a plurality of anchors coupled to aself-deforming coupling member or “backbone,” with the backbone shown inan undeployed shape and a deployed shape;

FIGS. 9A-9C are various perspective views of a distal portion of aflexible anchor delivery device according to one embodiment of thepresent invention;

FIGS. 10A-10F demonstrate a method for applying anchors to a valveannulus and cinching the anchors to tighten the annulus, using an anchordelivery device according to an embodiment of the invention;

FIG. 11 shows a heart in cross-section with a guide catheter deviceadvanced through the aorta into the left ventricle according to anembodiment of the invention;

FIG. 11A shows a distal end of an anchor delivery device passing througha guide catheter according to an embodiment of the invention;

FIG. 11B shows middle portions of an anchor delivery device and a guidecatheter having corresponding orientation portions according to anembodiment of the invention;

FIGS. 12A-12D show various embodiments of support members for supportingan anchor delivery device against a valve annulus;

FIGS. 13A-13C show a device and method for facilitating termination andload distribution of a series of anchors according to one embodiment ofthe invention;

FIGS. 14A-14F demonstrate a method for advancing an anchor deliverydevice to a position for treating a heart valve according to anembodiment of the invention;

FIGS. 15A and 15B are side cross-sectional views of a guide catheterdevice for facilitating positioning of an anchor delivery deviceaccording to an embodiment of the invention;

FIGS. 16A-16E show improved tissue anchors according to variousembodiments of the present invention;

FIGS. 17A-17C show a self-forming anchor attaching to tissue of a valveannulus according to one embodiment of the present invention;

FIG. 18 shows a self-forming anchor attaching to tissue of a valveannulus according to another embodiment of the present invention;

FIG. 19A shows an anchor device having a sleeve between two adjacentanchors according to one embodiment of the invention; and

FIG. 19B shows an anchor device having a sleeve between three anchorsaccording to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Devices, systems and methods of the present invention are generally usedto facilitate transvascular, minimally invasive and other “lessinvasive” surgical procedures, by facilitating the delivery of treatmentdevices at a treatment site. Although the following description focuseson use of devices and methods of the invention for mitral valve repair,the devices and methods may be used in any suitable procedure, bothcardiac and non-cardiac. When used for treatment of a cardiac valveannulus, the inventive methods generally involve contacting an anchordelivery device with a length of the valve annulus, delivering aplurality of coupled anchors from the anchor delivery device, anddrawing the anchors together to tighten the annulus. Devices include anelongate catheter having a housing at or near the distal end forreleasably housing a plurality of coupled anchors, as well as deliverydevices for facilitating advancement and/or positioning of an anchordelivery device. Devices may be positioned such that the housing abutsor is close to valve annular tissue, such as in a location within theleft ventricle defined by the left ventricular wall, a mitral valveleaflet and chordae tendineae. Self-securing anchors having any of anumber of different configurations may be used in some embodiments.Additional devices include delivery devices for facilitating deliveryand/or placement of an anchor delivery device at a treatment site.

In many cases, methods of the present invention will be performed on abeating heart. Access to the beating heart may be accomplished by anyavailable technique, including intravascular, transthoracic, and thelike. In addition to beating heart access, the methods of the presentinvention may be used for intravascular stopped heart access as well asstopped heart open chest procedures.

Referring now to FIG. 1, a heart H is shown in cross section, with anelongate anchor delivery device 100 introduced within the heart H.Generally, delivery device 100 comprises an elongate body with a distalportion 102 configured to deliver anchors to a heart valve annulus. (InFIGS. 1, 2A and 2B, distal portion 102 is shown diagrammatically withoutanchors or anchor-delivery mechanism to enhance clarity of the figures.)In some embodiments, the elongate body comprises a rigid shaft, while inother embodiments it comprises a flexible catheter, so that distalportion 102 may be positioned in the heart H and under one or more valveleaflets to engage a valve annulus via a transvascular approach.Transvascular access may be gained, for example, through the internaljugular vein (not shown) to the superior vena cava SVC to the rightatrium RA, across the interatrial septum to the left atrium LA, and thenunder one or more mitral valve leaflets MVL to a position within theleft ventricle (LV) under the valve annulus (not shown). Alternatively,access to the heart may be achieved via the femoral vein and theinferior vena cava. In other embodiments, access may be gained via thecoronary sinus (not shown) and through the atrial wall into the leftatrium. In still other embodiments, access may be achieved via a femoralartery and the aorta, into the left ventricle, and under the mitralvalve. This access route will be described in further detail below. Anyother suitable access route is also contemplated within the scope of thepresent invention.

In other embodiments, access to the heart H may be transthoracic, withdelivery device 100 being introduced into the heart via an incision orport on the heart wall. Even open heart surgical procedures may benefitfrom methods and devices of the invention. Furthermore, some embodimentsmay be used to enhance procedures on the tricuspid valve annulus,adjacent the tricuspid valve leaflets TVL, or any other cardiac orvascular valve. Therefore, although the following description typicallyfocuses on minimally invasive or less invasive mitral valve repair fortreating mitral regurgitation, the invention is in no way limited tothat use.

With reference now to FIGS. 2A and 2B, a method for positioning deliverydevice 100 for treating a mitral valve annulus VA is depicteddiagrammatically in a cross-sectional view. First, as in FIG. 2A, distalportion 102 is positioned in a desired location under a mitral valveleaflet L and adjacent a ventricular wall VW. (Again, distal portion 102is shown without anchors or anchor-delivery mechanism for demonstrativepurposes.) The valve annulus VA generally comprises an area of heartwall tissue at the junction of the ventricular wall VW and the atrialwall AW that is relatively fibrous and, thus, significantly strongerthat leaflet tissue and other heart wall tissue.

Distal portion 102 may be advanced into position under the valve annulusby any suitable technique, some of which are described below in furtherdetail. Generally, distal portion 102 may be used to deliver anchors tothe valve annulus, to stabilize and/or expose the annulus, or both. Inone embodiment, using a delivery device having a flexible elongate bodyas shown in FIG. 1, a flexible distal portion 102 may be passed from theright atrium RA through the interatrial septum in the area of theforamen ovale (not shown—behind the aorta A), into the left atrium LAand thus the left ventricle LV. Alternatively, flexible distal portion102 may be advanced through the aorta A and into the left ventricle LV,for example using access through a femoral artery. Oftentimes, distalportion 102 will then naturally travel, upon further advancement, underthe posterior valve leaflet L into a space defined above a subvalvularspace 104 roughly defined for the purposes of this application as aspace bordered by the inner surface of the left ventricular wall VW, theinferior surface of mitral valve leaflets L, and cordae tendineae CTconnected to the ventricular wall VW and the leaflet L. It has beenfound that a flexible anchor delivery catheter, such as the deliverydevices of the present invention, when passed under the mitral valve viaan intravascular approach, often enters subvalvular space 104 relativelyeasily and may be advanced along space 104 either partially orcompletely around the circumference of the valve. Once in space 104,distal portion 102 may be conveniently positioned at the intersection ofthe valve leaflet(s) and the ventricular wall VW, which intersection isimmediately adjacent or very near to the valve annulus VA, as shown inFIG. 2A. These are but examples of possible access routes of an anchordelivery device to a valve annulus, and any other access routes may beused.

In some embodiments, distal portion 102 includes a shape-changingportion which enables distal portion 102 to conform to the shape of thevalve annulus VA. The catheter may be introduced through the vasculaturewith the shape-changing distal portion in a generally straight, flexibleconfiguration. Once it is in place beneath the leaflet at theintersection between the leaflet and the interior ventricular wall, theshape of distal portion 102 is changed to conform to the annulus andusually the shape is “locked” to provide sufficient stiffness orrigidity to permit the application of force from distal portion 102 tothe annulus. Shaping and optionally locking distal portion 102 may beaccomplished in any of a number of ways. For example, in someembodiments, a shape-changing portion may be sectioned, notched, slottedor segmented and one of more tensioning members such as tensioningcords, wires or other tensioning devices coupled with the shape-changingportion may be used to shape and rigidify distal portion 102. Asegmented distal portion, for example, may include multiple segmentscoupled with two tensioning members, each providing a differentdirection of articulation to the distal portion. A first bend may becreated by tensioning a first member to give the distal portion aC-shape or similar shape to conform to the valve annulus, while a secondbend may be created by tensioning a second member to articulate theC-shaped member upwards against the annulus. In another embodiment, ashaped expandable member, such as a balloon, may be coupled with distalportion 102 to provide for shape changing/deforming. In variousembodiments, any configurations and combinations may be used to givedistal portion 102 a desired shape.

In transthoracic and other embodiments, distal portion 102 may beshaped, and the method may simply involve introducing distal portion 102under the valve leaflets. The shaped distal portion 102 may be rigid orformed from any suitable super-elastic or shape memory material, such asnitinol, spring stainless steel, or the like.

In addition to delivering anchors to the valve annulus VA, deliverydevice 100 (and specifically distal portion 102) may be used tostabilize and/or expose the valve annulus VA. Such stabilization andexposure are described fully in U.S. patent application Ser. No.10/656,797, which was previously incorporated by reference. For example,once distal portion 102 is positioned under the annulus, force may beapplied to distal portion 102 to stabilize the valve annulus VA, asshown in FIG. 2B. Such force may be directed in any suitable directionto expose, position and/or stabilize the annulus. For example, upwardand lateral force is shown in FIG. 2B by the solid-headed arrow drawnfrom the center of distal portion 102. In other cases, only upward, onlylateral, or any other suitable force(s) may be applied. With applicationof force to distal portion 102, the valve annulus VA is caused to riseor project outwardly, thus exposing the annulus for easier viewing andaccess. The applied force may also stabilize the valve annulus VA, alsofacilitating surgical procedures and visualization.

Some embodiments may include a stabilization component as well as ananchor delivery component. For example, some embodiments may include twoflexible members, one for contacting the atrial side of a valve annulusand the other for contacting the ventricular side. In some embodiments,such flexible members may be used to “clamp” the annulus between them.One of such members may be an anchor delivery member and the other maybe a stabilization member, for example. Any combination andconfiguration of stabilization and/or anchor delivery members iscontemplated.

Referring now to FIGS. 2C and 2D, an anchor delivery device 108 is showndelivering an anchor 110 to a valve annulus VA. Of course, these areagain representational figures and are not drawn to scale. Anchor 110 isshown first housed within delivery device 108 (FIG. 2C) and thendelivered to the annulus VA (FIG. 2D). As is shown, in one embodimentanchors 110 may have a relatively straight configuration when housed indelivery device 108, perhaps with two sharpened tips and a loop inbetween the tips. Upon deployment from delivery device 108, the tips ofanchor 110 may curve in opposite directions to form two semi-circles,circles, ovals, overlapping helices or the like. This is but one exampleof a type of self-securing anchor which may be delivered to a valveannulus. Typically, multiple coupled anchors 110 are delivered, and theanchors 110 are drawn together to tighten the valve annulus. Methods foranchor delivery and for drawing anchors together are described furtherbelow.

Although delivery device 108 is shown having a circular cross-sectionalshape in FIGS. 2C and 2D, it may alternatively have any other suitableshape. In one embodiment, for example, it may be advantageous to providea delivery device having an ovoid or elliptical cross-sectional shape.Such a shape may help ensure that the device is aligned, when positionedbetween in a corner formed by a ventricular wall and a valve leaflet,such that one or more openings in the delivery device is oriented todeliver the anchors into valve annulus tissue. To further enhancecontacting of the valve annulus and/or orientation of the deliverydevice, some embodiments may further include an expandable member,coupled with the delivery device, which expands to urge or press orwedge the delivery device into the corner formed by the ventricle walland the leaflet to contact the valve annulus. Such enhancements aredescribed further below.

With reference now to FIG. 3, one embodiment of a portion of an anchordelivery device 200 suitably includes an elongate shaft 204 having adistal portion 202 configured to deliver a plurality of anchors 210,coupled with a tether 212, to tissue of a valve annulus. Tetheredanchors 210 are housed within a housing 206 of distal portion 202, alongwith one or more anchor retaining mandrels 214 and an expandable member208. Many variations may be made to one or more of these features, andvarious parts may be added or eliminated, without departing from thescope of the invention. Some of these variations are described furtherbelow, but no specific embodiment(s) should be construed to limit thescope of the invention as defined by the appended claims.

Housing 206 may be flexible or rigid in various embodiments. In someembodiments, for example, flexible housing 206 may be comprised ofmultiple segments configured such that housing 206 is deformable bytensioning a tensioning member coupled to the segments. In someembodiments, housing 206 is formed from an elastic material having ageometry selected to engage and optionally shape or constrict the valveannulus. For example, the rings may be formed from super-elasticmaterial, shape memory alloy such as Nitinol, spring stainless steel, orthe like. In other instances, housing 206 could be formed from aninflatable or other structure can be selectively rigidified in situ,such as a gooseneck or lockable element shaft, any of the rigidifyingstructures described above, or any other rigidifying structure.

“Anchors,” for the purposes of this application, is defined to mean anyfasteners. Thus, anchors 210 may comprise C-shaped or semicircularhooks, curved hooks of other shapes, straight hooks, barbed hooks, clipsof any kind, T-tags, or any other suitable fastener(s). In oneembodiment, as described above, anchors may comprise two tips that curvein opposite directions upon deployment, forming two intersectingsemi-circles, circles, ovals, helices or the like. In some embodiments,anchors 210 are self-deforming. By “self-deforming” it is meant thatanchors 210 change from a first undeployed shape to a second deployedshape upon release of anchors 210 from restraint in housing 206. Suchself-deforming anchors 210 may change shape as they are released fromhousing 206 and enter valve annulus tissue, to secure themselves to thetissue. Thus, a crimping device or other similar mechanism is notrequired on distal end 202 to apply force to anchors 210 to attach themto annular tissue.

Self-deforming anchors 210 may be made of any suitable material, such asa super-elastic or shape-memory material like Nitinol or springstainless steel. In other embodiments, anchors 210 may be made of anon-shape-memory material and made be loaded into housing 206 in such away that they change shape upon release. Alternatively, anchors 210 thatare not self-deforming may be used, and such anchors may be secured totissue via crimping, firing or the like. Even self-securing anchors maybe crimped in some embodiments, to provide enhanced attachment totissue. In some embodiments, anchors 210 may comprise one or morebioactive agent. In another embodiment, anchors 210 may compriseelectrodes. Such electrodes, for example, may sense various parameters,such as but not limited to impedance, temperature and electricalsignals. In other embodiments, such electrodes may be used to supplyenergy to tissue at ablation or sub-ablation amounts. Delivery ofanchors may be accomplished by any suitable device and technique, suchas by simply releasing the anchors by hydraulic balloon delivery asdiscussed further below. Any number, size and shape of anchors 210 maybe included in housing 206.

In one embodiment, anchors 210 are generally C-shaped or semicircular intheir undeployed form, with the ends of the C being sharpened topenetrate tissue. Midway along the C-shaped anchor 210, an eyelet may beformed for allowing slidable passage of tether 212. To maintain anchors210 in their C-shaped, undeployed state, anchors 210 may be retainedwithin housing 206 by two mandrels 214, one mandrel 214 retaining eachof the two arms of the C-shape of each anchor 210. Mandrels 214 may beretractable within elongate catheter body 204 to release anchors 210 andallow them to change from their undeployed C-shape to a deployed shape.The deployed shape, for example, may approximate a complete circle or acircle with overlapping ends, the latter appearing similar to a keyring. Such anchors are described further below, but generally may beadvantageous in their ability to secure themselves to annular tissue bychanging from their undeployed to their deployed shape. In someembodiments, anchors 210 are also configured to lie flush with a tissuesurface after being deployed. By “flush” it is meant that no significantamount of an anchor protrudes from the surface, although some smallportion may protrude.

Tether 212 may be one long piece of material or two or more pieces andmay comprise any suitable material, such as suture, suture-likematerial, a Dacron strip or the like. Retaining mandrels 214 may alsohave any suitable configuration and be made of any suitable material,such as stainless steel, titanium, Nitinol, or the like. Variousembodiments may have one mandrel, two mandrels, or more than twomandrels.

In some embodiments, anchors 210 may be released from mandrels 214 tocontact and secure themselves to annular tissue without any furtherforce applied by delivery device 200. Some embodiments, however, mayalso include one or more expandable members 208, which may be expandedto help drive anchors 210 into tissue. Expandable member(s) 208 may haveany suitable size and configuration and may be made of any suitablematerial(s). Hydraulic systems such as expandable members are known inthe art, and any known or as yet undiscovered expandable member may beincluded in housing 206 as part of the present invention.

Referring now to FIGS. 4 and 5, a segment of a distal portion 302 of ananchor delivery device suitably includes a housing 306, multipletensioning members 320 for applying tension to housing 306 to change itsshape, two anchor retaining mandrels 314 slidably disposed in housing306, multiple anchors 310 slidably coupled with a tether 312, and anexpandable member 308 disposed between anchors 310 and housing 306. Ascan be seen in FIGS. 4 and 5, housing 306 may include multiple segmentsto allow the overall shape of housing 306 to be changed by applyingtension to tensioning members 320. As also is evident from the drawings,“C-shaped” anchors 310 may actually have an almost straightconfiguration when retained by mandrels 314 in housing 306. Thus, forthe purposes of this application, “C-shaped” or “semicircular” refers toa very broad range of shapes including a portion of a circle, a slightlycurved line, a slightly curved line with an eyelet at one point alongthe line, and the like.

With reference now to FIG. 6, the same segment of distal portion 302 isshown, but mandrels 314 have been withdrawn from two mandrel apertures322, to release anchors 310 from housing 306. Additionally, expandablemember 308 has been expanded to drive anchors out of housing 306.Anchors 310, having been released from mandrels 314, have begun tochange from their undeployed, retained shape to their deployed, releasedshape.

Referring now to FIGS. 7A-7E, a cross-section of a distal portion 402 ofan anchor delivery device is shown in various stages of delivering ananchor to tissue of a valve annulus VA. In FIG. 7A, distal portion 402is positioned against the valve annulus, an anchor 410 is retained bytwo mandrels 414, a tether 412 is slidably disposed through an eyelet onanchor 410, and an expandable member 408 is coupled with housing 406 ina position to drive anchor 410 out of housing 406. When retained bymandrels 414, anchor 410 is in its undeployed shape. As discussed above,mandrels 414 may be slidably retracted, as designated by thesolid-tipped arrows in FIG. 7A, to release anchor 410. In variousembodiments, anchors 410 may be released one at a time, such as byretracting mandrels 414 slowly, may be released in groups, or may all bereleased simultaneously, such as by rapid retraction of mandrels 414.

In FIG. 7B, anchor 410 has begun to change from its undeployed shape toits deployed shape (as demonstrated by the hollow-tipped arrows) and hasalso begun to penetrate the annular tissue VA. Empty mandrel apertures422 demonstrate that mandrels 414 have been retracted at least farenough to release anchor 410. In FIG. 7B, expandable member 408 has beenexpanded to drive anchor 410 partially out of housing 406 and furtherinto the valve annulus VA. Anchor 410 also continues to move from itsundeployed towards its deployed shape, as shown by the hollow-tippedarrows. In FIG. 7D, anchor 410 has reached its deployed shape, which isroughly a completed circle with overlapping ends or a “key ring” shape.In FIG. 7E, delivery device 402 has been removed, leaving a tetheredanchor in place in the valve annulus. Of course, there will typically bea plurality of tethered anchors secured to the annular tissue. Tether412 may then be cinched to apply force to anchors 410 and cinch andtighten the valve annulus.

With reference now to FIGS. 8A and 8B, a diagrammatic representation ofanother embodiment of coupled anchors is shown. Here, anchors 510 arecoupled to a self-deforming or deformable coupling member or backbone505. Backbone 505 may be fabricated, for example, from Nitinol, springstainless steel, or the like, and may have any suitable size orconfiguration. In one embodiment, as in FIG. 8A, backbone 505 is shapedas a generally straight line when held in an undeployed state, such aswhen restrained within a housing of an anchor deliver device. Whenreleased from the delivery device, backbone 505 may change to a deployedshape having multiple bends, as shown in FIG. 8B. By bending, backbone505 shortens the longitudinal distance between anchors, as demonstratedby the solid-tipped arrows in FIG. 8B. This shortening process may actto cinch a valve annulus into which anchors 510 have be secured. Thus,anchors 510 coupled to backbone 505 may be used to cinch a valve annuluswithout using a tether or applying tethering force. Alternatively, atether may also be coupled with anchors 510 to further cinch theannulus. In such an embodiment, backbone 505 will be at least partiallyconformable or cinchable, such that when force is applied to anchors 510and backbone 505 via a tether, backbone 505 bends further to allowfurther cinching of the annulus.

Referring now to FIGS. 9A-9C, in one embodiment a flexible distalportion of an anchor delivery device 520 suitably includes a housing 522coupled with an expandable member 524. Housing 522 may be configured tohouse multiple coupled anchors 526 and an anchor contacting member 530coupled with a pull cord 532. Housing 522 may also include multipleapertures 528 for allowing egress of anchors 526. For clarity, deliverydevice 520 is shown without a tether in FIGS. 9A and 9C, but FIG. 9Bshows that a tether 534 may extend through an eyelet, loop or otherportion of each anchor 526, and may exit each aperture 528 to allow forrelease of the plurality of anchors 526. The various features of thisembodiment are described further below.

In the embodiment shown in FIGS. 9A-9C, anchors 526 are relativelystraight and lie relatively in parallel with the long axis of deliverydevice 522. Anchor contacting member 530, which may comprise anysuitable device, such as a ball, plate, hook, knot, plunger, piston, orthe like, generally has an outer diameter that is nearly equal to orslightly less than the inner diameter of housing 522. Contacting member530 is disposed within the housing, distal to a distal-most anchor 526,and is retracted relative to housing 522 by pulling pull cord 532. Whenretracted, anchor contacting member 530 contacts and applies force to adistal-most anchor 526 to release cause that anchor 526 to exit housing522 via one of the apertures 528. Contacting member 530 is then pulledfarther proximally to contact and apply force to the next anchor 526 todeploy that anchor 526, and so on.

Retracting contacting member 530 to push anchors 526 out of apertures528 may help cause anchors 526 to avidly secure themselves to adjacenttissue. Using anchors 526 that are relatively straight/flat whenundeployed allows anchors 526 with relatively large deployed sizes to bedisposed in (and delivered from) a relatively small housing 522. In oneembodiment, for example, anchors 526 that deploy into a shapeapproximating two intersecting semi-circles, circles, ovals, helices, orthe like, and that have a radius of one of the semi-circles of about 3mm may be disposed within a housing 522 having a diameter of about 5French (1.67 mm) and more preferably 4 French (1.35 mm) or even smaller.Such anchors 526 may measure about 6 mm or more in their widestdimension. In some embodiments, housing 522 may have a diametricaldimension (“d”) and anchor 526 may have a diametrical dimension (“D”) inthe deployed state, and the ratio of D to d may be at least about 3.5.In other embodiments, the ratio of D to d may be at least about 4.4, andmore preferably at least about 7, and even more preferably at leastabout 8.8. These are only examples, however, and other larger or smalleranchors 526 may be disposed within a larger or smaller housing 522.Furthermore, any convenient number of anchors 526 may be disposed withinhousing 522. In one embodiment, for example, housing 522 may hold about1-20 anchors 526, and more preferably about 3-10 anchors 526. Otherembodiments may hold more anchors 526.

Anchor contacting member 530 and pull cord 532 may have any suitableconfiguration and may be manufactured from any material or combinationof materials. In alternative embodiments, contacting member 530 may bepushed by a pusher member to contact and deploy anchors 526.Alternatively, any of the anchor deployment devices and methodspreviously described may be used.

Tether 534, as shown in FIG. 9B, may comprise any of the tethers 534 ortether-like devices already described above, or any other suitabledevice. Tether 534 is generally attached to a distal-most anchor 526 atan attachment point 536. The attachment itself may be achieved via aknot, weld, adhesive, or by any other suitable attachment means. Tether234 then extends through an eyelet, loop or other similar configurationon each on each of the anchors 526 so as to be slidably coupled with theanchors 526. In the embodiment shown, tether 534 exits each aperture528, then enters the next-most-proximal aperture, passes slidablythrough a loop on an anchor 526, and exits the same aperture 528. Byentering and exiting each aperture 528, tether 534 allows the pluralityof anchors 526 to be deployed into tissue and cinched. Otherconfigurations of housing 522, anchors 526 and tether 534 mayalternatively be used. For example, housing 522 may include alongitudinal slit through which tether 534 may pass, thus allowingtether 534 to reside wholly within housing before deployment.

Expandable member 524 is an optional feature of anchor delivery device520, and thus may be included in some embodiments and not in others. Inother words, a distal portion of anchor delivery device 520 may includehousing, contents of housing, and other features either with or withoutan attached expandable member. Expandable member 524 may comprise anysuitable expandable member currently known or discovered in the future,and any method and substance(s) may be used to expand expandable member524. Typically, expandable member 524 will be coupled with a surface ofhousing 522, will have a larger radius than housing 522, and will beconfigured such that when it is expanded as housing 522 nears orcontacts the valve annulus, expandable member 524 will push or presshousing 522 into enhanced contact with the annulus. For example,expandable member 524 may be configured to expand within a space nearthe corner formed by a left ventricular wall and a mitral valve leaflet.

With reference now to FIGS. 10A-10F, a method is shown for applying aplurality of tethered anchors 526 to a valve annulus VA in a heart. Asshown in FIG. 10A, an anchor delivery device 520 is first contacted withthe valve annulus VA such that openings 528 are oriented to deployanchors 526 into the annulus. Such orientation may be achieved by anysuitable technique. In one embodiment, for example, a housing 522 havingan elliptical cross-sectional shape may be used to orient openings 528.As just described, contact between housing 522 and the valve annulus VAmay be enhanced by expanding expandable member 524 to wedge housingwithin a corner adjacent the annulus.

Generally, delivery device 520 may be advanced into any suitablelocation for treating any valve by any suitable advancing or deviceplacement method. Many catheter-based, minimally invasive devices andmethods for performing intravascular procedures, for example, are wellknown, and any such devices and methods, as well as any other devices ormethod later developed, may be used to advance or position deliverydevice 520 in a desired location. For example, in one embodiment asteerable guide catheter is first advanced in retrograde fashion throughan aorta, typically via access from a femoral artery. The steerablecatheter is passed into the left ventricle of the heart and thus intothe space formed by the mitral valve leaflets, the left ventricular walland cordae tendineae of the left ventricle. Once in this space, thesteerable catheter is easily advanced along a portion (or all) of thecircumference of the mitral valve. A sheath is advanced over thesteerable catheter within the space below the valve leaflets, and thesteerable catheter is removed through the sheath. Anchor delivery device520 may then be advanced through the sheath to a desired position withinthe space, and the sheath may be removed. In some cases, an expandablemember coupled to delivery device 520 may be expanded to wedge orotherwise move delivery device 520 into the corner formed by the leftventricular wall and the valve leaflets to enhance its contact with thevalve annulus. Of course, this is but one exemplary method for advancingdelivery device 520 to a position for treating a valve, and any othersuitable method, combination of devices, etc. may be used.

As shown in FIG. 10B, when delivery device 520 is positioned in adesired location for deploying anchors 526, anchor contacting member 530is retracted to contact and apply force to a most-distal anchor 526 tobegin deploying anchor 526 through aperture 528 and into tissue of thevalve annulus VA. FIG. 10C show anchor 526 further deployed out ofaperture 528 and into valve annulus VA. FIG. 10D shows the valve annulusVA transparently so that further deployment of anchors 526 can be seen.As shown, in one embodiment of the invention, anchors 526 include twosharpened tips that move in opposite directions upon release fromhousing 522 and upon contacting the valve annulus VA. Between the twosharpened tips, an anchor 526 may be looped or have any other suitableeyelet or other device for allowing slidable coupling with a tether 534.

Referring now to FIG. 10E, anchors 526 are seen in their fully deployedor nearly fully deployed shape, with each pointed tip (or “arm”) of eachanchor 526 having curved to form a circle or semi-circle. Of course, invarious embodiments anchors 526 may have any other suitable deployed andundeployed shapes, as described more fully above. FIG. 10F shows anchors526 deployed into the valve annulus VA and coupled with tether 534, withthe distal-most anchor 526 coupled attached fixedly to tether 524 atattachment point 536. At this stage, tether 534 may be cinched totighten the annulus, thus reducing valve regurgitation. In someembodiments, valve function may be monitored by means such asechocardiogram and/or fluoroscopy, and tether 534 may be cinched,loosened, and adjusted to achieve a desired amount of tightening asevident via the employed visualization technique(s). When a desiredamount of tightening is achieved, tether 534 is then attached to amost-proximal anchor 526 (or two or more most-proximal anchors 526),using any suitable technique, and tether 534 is then cut proximal to themost-proximal anchor 526, thus leaving the cinched, tethered anchors 526in place along the valve annulus VA. Attachment of tether 534 to themost-proximal anchor(s) 526 may be achieved via adhesive, knotting,crimping, tying or any other technique, and cutting tether 534 may alsobe performed via any technique, such as with a cutting member coupledwith housing 522.

In one embodiment, cinching tether 534, attaching tether 534 tomost-proximal anchor 526, and cutting tether 534 are achieved using atermination device (not shown). The termination device may comprise, forexample, a catheter advancable over tether 534 that includes a cuttingmember and a nitinol knot or other attachment member for attachingtether 534 to most-proximal anchor. The termination catheter may beadvanced over tether 534 to a location at or near the proximal end ofthe tethered anchors 526. It may then be used to apply opposing force tothe most-proximal anchor 526 while tether 534 is cinched. Attachment andcutting members may then be used to attach tether 534 to most-proximalanchor 526 and cut tether 534 just proximal to most-proximal anchor 526.Such a termination device is only one possible way of accomplishing thecinching, attachment and cutting steps, and any other suitable device(s)or technique(s) may be used.

In some embodiments, it may be advantageous to deploy a first number ofanchors 526 along a first portion of a valve annulus VA, cinch the firstanchors to tighten that portion of the annulus, move the delivery device520 to another portion of the annulus, and deploy and cinch a secondnumber of anchors 526 along a second portion of the annulus. Such amethod may be more convenient, in some cases, than extending deliverydevice 520 around all or most of the circumference of the annulus, andmay allow a shorter, more maneuverable housing 522 to be used.

In an embodiment similar to that shown in FIGS. 10A-10F, an analogousmethod may be used but anchors 526 may be driven out of delivery device520 through a biocompatible material attached to delivery device 520,thereby attaching the biocompatible material to the valve annulus VA.For example, in one embodiment a Dacron strip may be attached todelivery device 520, extending along device 520 and covering apertures528. Anchors 526 are then driven out of delivery device 520, through theDacron strip, into the valve annulus VA, thus detaching the Dacron stripfrom device 520 and attaching it to the valve annulus VA. Such abiocompatible material may facilitate tissue ingrowth of anchors 526 andmay enhance attachment generally to the valve annulus VA. In analternative embodiment, multiple pieces of biocompatible material, suchas separate pieces of material disposed over each of apertures 528, maybe used. For example, in one embodiment multiple discs of Dacronmaterial are disposed over multiple apertures 528.

In another embodiment, a distal portion of delivery device 520 may bedetachable from a proximal portion of delivery device 520. Such anembodiment may be configured such that when anchors 526 are deployedfrom device 520, the distal portion of device 520 detaches from theproximal portion and is attached, via anchors 526, to the valve annulusVA. In one embodiment, for example, anchors 526 may pierce through thedistal portion of device 520, rather than exiting device 520 throughapertures 528. The distal portion may be detachable via any suitablemeans, such as perforations or the like.

Referring now to FIG. 11, a cross-sectional depiction of a heart H isshown with an anchor delivery device guide catheter 550 advanced throughthe aorta A and into the left ventricle LV. In a preferred embodiment,this access route to the subannular space and the valve annulus mayused. Guide catheter 550 is generally a flexible elongate catheter whichmay have one or more curves or bends toward its distal end to facilitateplacement of the distal end of catheter 550 in a subannular space 552.Subannular space 552, which has been described above in detail, isgenerally defined by the left ventricular wall, the mitral valveleaflets MVL, and cordae tendiniae, and travels along most or all of thecircumference of the valve annulus. The distal end of guide catheter 550may be configured to be positioned at an opening into space 552 orwithin space 552, such that subsequent catheter devices may be passedthrough guide catheter 550 into space 552. In some embodiments, it maybe advantageous to provide guide catheter 550 with a curvable portionwith a radius in an expanded/curved state that is greater than a radiusof the valve annulus. For example, in one embodiment guide catheter 550in the expanded state has a radius about 25%-50% larger that the valveannulus.

With reference now to FIG. 11A, a distal portion of guide catheter 550is shown, with an anchor delivery device 558 extending through it andout of its distal end. As shown, in one embodiment guide catheter 550includes at least one bend 551 or curvature, and anchor delivery device558 is pre-shaped to include at least one corresponding bend 553, thathas approximately the same radius of curvature as the bend 551 in guidecatheter 550. In some embodiments (not shown), guide catheter 550 mayhave multiple bends 551, and anchor delivery device 558 may havemultiple corresponding bends 553. In the embodiment shown, anchordelivery device 558 includes a proximal bend 553, which corresponds tothe bend 551 in guide catheter 550, and a distal bend 555. By matchingthe radii of curvature of the proximal bend 553 and the guide catheterbend 551, the distal portion of anchor delivery device 558 becomesautomatically oriented (when advanced through guide catheter 550) suchthat one or more anchor delivery apertures 557 are in contact with thevalve annulus (not shown). Moreover, distal bend 555 may have a radiusof curvature that matches approximately a radius of curvature of a valveannulus. Alternatively, distal bend 555 may have a radius of curvaturegreater than a valve annulus radius of curvature, such that the distalportion of anchor delivery device 558 tends to push radially outward,enhancing contact of the device 558 with valve annulus tissue. Suchgreater radii of curvature are described in greater detail below.Proximal bend 553 and distal bend 555 may therefore have any suitableangles relative to one another and relative to the more proximal portionof anchor delivery device 558. In some embodiments, anchor deliverydevice 558 is also steerable.

With reference now to FIG. 11B, in the embodiment described immediatelyabove and/or in alternative embodiments, an anchor delivery device 588and a guide catheter 590 may include one or more corresponding (or“registering”) bends or orientation portions 592 a, 592 b at otherlocations along their lengths. In other words, although bends 551, 553,555 are shown in FIG. 11A at or near the distal ends of guide catheter550 and anchor delivery device 558, similar bends could be formed atmore proximal locations. For example, FIG. 11B shows guide catheter 590with orientation portion 592 a having a chosen shape when relaxed. Thechosen shape may lie along a two-dimensional or three-dimensional path.Anchor delivery device 588 has a corresponding orientation portion 592 balong its length which is complementary to the shape of orientationportion 592 a. The chosen shape may also be created by the applicationof energy, mechanical manipulation or the like. Such orientationportions 592 a, 592 b could be used for further registering or orientingdelivery device 588 to a desired orientation. Typically, whenorientation portions 592 a, 592 b are axially aligned, which can beindicated by orientation markers at the proximal ends of guide catheter590 and anchor delivery device 588 external of the patient, properrotary orientation can be sensed tactically by the physician to helpinsure the distal end of anchor delivery device 588 is properlyoriented. Delivery device 588 may be rotated, advanced or moved in anysuitable fashion within guide catheter 590 to achieve a desiredorientation. The use of one or more complementary orientation portions592 a, 592 b may be used with any of a number of various embodiments ofguide catheters and anchor delivery devices.

In a number of cases, and with reference now to FIGS. 12A-12D, it may beadvantageous to provide further support to an anchor delivery device658, to support the device 658 against valve annulus tissue and/or topush the device 658 against valve annulus tissue to enhance contactwith, and anchor delivery into, the tissue. In one embodiment, as shownin FIG. 12A, a helical support member 652 may be coupled with a distalend of anchor delivery device 658 and may be extended into the leftventricle of a heart (or other heart chamber in other embodiments) tocontact the heart wall 651 and thus support anchor delivery device 658against the valve annulus tissue. In alternative embodiments, helicalsupport member 651 may extend out of a guide catheter 650 to contact theheart wall 651 and support anchor delivery device 658. Any suitablemeans may be used for extending helical member 652 into the leftventricle or other chamber. For example, helical member 652 is pushedout of guide catheter 650 in one embodiment, but may alternatively beextended out of anchor delivery device 658. Helical member 652 may bemade of any suitable material, such as but not limited to Nitinol,stainless steel or the like.

In an alternative embodiment, pictured in FIG. 12B, a deployableU-shaped support member 662 may be movably coupled with a distal portionof an anchor delivery device 668, both of which are advanceable througha guide catheter 660. Upon being advanced out of the distal end of guidecatheter 660, U-shaped member 662 may automatically spring out, oralternatively may be manually manipulated to extend outward, to contactthe inner surface of the heart wall and/or to contact a papillary muscle663. As shown in FIG. 12B, in one embodiment U-shaped member 663contacts an intersection of a papillary muscle 663 with the heart wall,and thus provides upward support (solid-tipped arrows) to anchordelivery device 668. Again, such a U-shaped member 662 may automaticallydeform from a straight configuration for delivery through guide catheter660 into a U-shaped configuration, such as if member 662 is made ofNitinol, spring stainless steel, or other shape memory or super-elasticmaterial. Alternatively, U-shaped member 662 may be connected to anchordelivery device 668 at or near the distal end of the device 668 and maybe pushed distally to force the U-shaped member 662 to expand into itsU-shape. In an alternative embodiment, U-shaped member 662 may beattached proximally and may be pulled into its expanded configuration.Any suitable method for changing the shape of U-shaped member 662 fromstraight to U-shaped may be used in various embodiments.

As shown in FIG. 12C, U-shaped member 662 may optionally include anexpandable member 667, such as an inflatable balloon. Expandable member667 may be expanded to provide further force against and support ofanchor delivery device 668, to enhance its contact with valve annulustissue. In another embodiment, as shown in FIG. 12D, multiple springmembers 672 may be coupled with a distal end of an anchor deliverydevice 678 to provide force against an inner surface of a heart wall(solid tipped arrows) to thus support anchor delivery device 678 againstannulus tissue (hollow tipped arrows). Thus, various embodiments of theinvention may include any of a number of suitable support devices forenhancing support of an anchor delivery device against valve annulustissue, thus enhancing the ability of the delivery device to deliverytissue anchors into the annulus.

Referring now to FIGS. 13A-13C, in some embodiments it may beadvantageous to provide one or more devices to enhance the attachment ofa terminal tissue anchor 710 to valve annulus tissue VA. Typically, inattaching tissue anchors to valve annulus tissue VA, a first tetheredanchor (not shown) is attached, and subsequent anchors are thenattached, ending in a final or terminal anchor 710. A tether 718 is thencinched, to apply force between the attached anchors (hollow arrow),thus cinching the valve annulus VA. Tether 718 is then typicallyattached by any suitable means to terminal anchor 710 and then cut orotherwise detached proximal to the terminal anchor 710, leaving thecinched, tethered anchors in place, attached to the valve annulus VA. Torelieve some of the tension placed on terminal anchor 710 and/or toprovide additional attachment/anchoring strength to the terminal end ofthe tethered anchors, one or more locking members 714 may be deployed ator near the terminal end. For example, in one embodiment locking member714 comprises a cylinder slidably disposed over tether 718, with prongs712 extending from one end of the cylinder. Locking member 714 isdeployed out of the distal end of a termination catheter, guide catheteror the like (not shown) and is then slid along tether 718, such thatprongs 712 contact and enter into valve annulus tissue VA. In oneembodiment, a pusher member 716, such as a ball slidably disposed overtether 718, may be used to push locking member 714 forward and intoengagement with tissue, as shown in FIG. 13B and as designated by solidtipped arrows. In some embodiments, locking member 714 engages withterminal anchor 710, as shown in FIGS. 13B and 13C, though suchengagement is not required. Once locking member 714 is fully engagedwith valve tissue VA, tether 718 is cut proximal to locking member 714.In some embodiments, pusher member 716 remains in place, while in othersit may be removed before cutting tether 718.

A number of different variations of locking members are contemplated invarious embodiments. For example, a two-pronged member may be used, withthe prongs deployable from a delivery position to and expandedconfiguration, and with the prongs optionally engaging with the terminalanchor 710. In another embodiment, multiple prongs may be aligned in alinear fashion along a locking member, such as in a rake-likeconfiguration. Yet another embodiment include two prongs for engagingwith the terminal anchor 710 and another prong for engaging with valveannulus tissue VA. Thus, any of a number of different embodiments may beemployed as part of the present invention. Such locking members may beconstructed from any suitable material or combination of materials, suchas Nitinol, spring stainless steel and/or other shape memory orsuper-elastic materials.

FIGS. 14A-14F demonstrate a method for advancing an anchor deliverydevice to a position for treating a mitral valve MV. The mitral valveMV, including mitral valve leaflets MVL are represented diagrammaticallyfrom an inferior perspective looking up, to depict a method fordelivering a device into subannular space 552. In FIG. 14A, first guidecatheter 550 is show extending up to or into subannular space 552, as inFIG. 11. As shown in FIG. 14B, in one method a second guide catheter 554may be advanced through first guide catheter 550 to pass through/alongsubannular space 554. This second guide catheter 554 is steerable in oneembodiment, as will be described further below, to help conform secondguide catheter 554 to subannular space 552.

Next, as in FIG. 14C, a guide sheath 556 may be passed over second guidecatheter 554 to extend along subannular space. Sheath 556 is generally aflexible, tubular member that can be passed over second guide catheter554 and within first guide catheter 550. To enhance passage andexchange, any of these and other described catheter members, sheathmembers, or the like may be manufactured from and/or coated with one ormore friction resistant materials. Once sheath 556 is in place, secondguide catheter 554 may be withdrawn, as shown in FIG. 14D. As shown inFIG. 14E, an anchor delivery device 558 may then be advanced throughsheath 556 to a position for treating the mitral valve MV. Sheath 556may then be withdrawn, as in FIG. 14F, leaving anchor delivery device558 in place for performing a treatment. A valve annulus treatment maybe performed, as described extensively above, and anchor delivery device558 may be withdrawn. In some embodiments, anchor delivery device 558 isused to treat one portion of the valve annulus and is then moved toanother portion, typically the opposite side, to treat the other portionof the annulus. In such embodiments, any one or more of the steps justdescribed may be repeated. In some embodiments, anchor delivery device558 is withdrawn through first guide catheter 550, and first guidecatheter 550 is then withdrawn. In alternative embodiments, first guidecatheter 550 may be withdrawn before anchor delivery device 558.

In various embodiments, alternative means may be used to urge anchordelivery device 558 into contact with the valve annulus. For example, inone embodiment an expandable member is coupled with anchor deliverydevice 558 and expanded within the subannular space 552. In analternative embodiment, a magnet may be coupled with anchor deliverydevice 558, and another anchor may be disposed within the coronarysinus, in proximity to the first magnet. The two magnets may attract oneanother, thus pulling the anchor delivery device 558 into greatercontact with the annulus. In another embodiment, anchor delivery device558 in an expanded (or deployed) state may have a radius of curvaturethat is larger than the radius of curvature of the mitral valve annulus,thus causing device 558 to be urged against the annulus. In oneembodiment, for example, the radius of curvature of device 558 in theexpanded/deployed state is about 25%-50% larger than the radius ofcurvature of the mitral valve annulus.

Various embodiments may also include visualizing the annulus using avisualization member coupled with the anchor delivery device 558 orseparate from the device 558. In some embodiments, anchors may be driventhrough a strip of detachable, biocompatible material, such as Dacron,that is coupled with anchor delivery device 558 but that detaches toaffix to the valve annulus via the anchors. In some embodiments, thestrip may then be cinched to tighten the annulus. In other embodiments,the anchors may be driven through a detachable, biocompatible, distalportion of the guide sheath 556, and guide sheath 556 may then remainattached to the annulus via the anchors. Again, in some embodiments, thedetached sheath may be cinched to tighten the annulus.

Of course, the method just described is but one embodiment of a methodfor delivering an anchor delivery device to a location for treating avalve annulus. In various alternative embodiments, one or more steps maybe added, deleted or modified while achieving a similar result. In someembodiments, a similar method may be used to treat the mitral valve froma superior/right atrial position or to treat another heart valve.Additionally, other devices or modifications of the system justdescribed may be used in other embodiments.

With reference now to FIGS. 15A and 15B, one embodiment of a steerablecatheter device 560 is shown. Steerable catheter device 560 may be usedin a method such as that just described in reference to FIGS. 14A-14F,for example in performing a function similar to that performed by secondguide catheter 554. In other embodiments, catheter device 560 mayperform any other suitable function. As shown, catheter device 560suitably includes an elongate catheter body having a proximal portion562 and a distal portion 564. At least one tensioning member 568, suchas but not limited to a tensioning cord, extends from proximal portion562 to distal portion 564 and is coupled with the distal portion 564 andat least one tensioning actuator 570/572 on the proximal portion.Tensioning actuator 570/572 may include, for example, a knob 570 and abarrel 572 for wrapping and unwrapping tensioning member 568 to applyand remove tension. Tensioning member 568 is coupled with distal portion564 at one or more connection points 580. In some embodiments, catheterdevice 560 includes a proximal housing 571, handle or the like, coupledto the proximal end of proximal portion 562 via a hub 576 or othermeans. Housing 571 may be coupled with tensioning actuator 570/572 andmay include one or more arms 574 for infusing fluid or for otherfunctions. In the embodiment shown, arm 574 and housing 571 include alumen 567 that is in fluid communication with a fluid lumen 566 of thecatheter body. Fluid may be introduced through arm 574 to pass throughfluid lumen 566 to provide, for example, for contrast material at thedistal tip of catheter device 560 to enhance visualization of device 560during a procedure. Any other suitable fluid(s) may be passed throughlumens 567/566 for any other purpose. Another lumen 578 may be includedin distal portion 564, through which tensioning member 568 passes beforeattaching at a distal location along distal portion 564.

FIG. 15B shows catheter device 560 in a deformed/bent configuration,after tension has been applied to distal portion 564 by applying tensionto tensioning member 568, via knob 570 and barrel 572. The bend indistal portion 564 will allow it to conform more readily to a valveannulus, while catheter device 560 in its straight configuration will bemore amenable to passage through vasculature of the patient. Tensioningmember 568 may be manufactured from any suitable material or combinationof materials, such as but not limited to Nitinol, polyester, nylon,polypropylene and/or other polymers. Some embodiments may include two ormore tensioning members 568 and/or two or more tensioning actuators570/572 to provide for changes in shape of distal portion 564 inmultiple directions. In alternative embodiments, knob 570 and barrel 572may be substituted with any suitable devices, such as a pull cord,button, lever or other actuator. Various alternatives may also besubstituted for tensioning member 568 in various embodiments. Forexample, shaped expandable members, shape memory members and/or the likemay be used to change the shape of distal portion 564.

Generally, proximal portion 562 of the catheter body is less flexiblethan distal portion 564. Proximal portion 562 may be made of anysuitable material, such as PEBAX, FEP, nylon, polyethylene and/or thelike, and may include a braided material, such as stainless steel, toprovide stiffness and strength. Distal portion 564 may be made ofsimilar or other materials, but the braided material is typically notincluded, to provide for greater flexibility. Both proximal and distalportions 562/564 may have any suitable lengths, diameters, overallconfigurations and the like. In one embodiment the catheter body isapproximately 140 cm in length and 6 French in diameter, but any othersuitable sizes may be used in other embodiments. Either proximal portion562, distal portion 564 or preferably both, may be made from or coatedwith one or more friction resistant or lubricating material to enhancepassage of device 560 through an introducer catheter and/or to enhancepassage of a sheath or other device over catheter device 560.

With reference now to FIGS. 16A-16E, another aspect of the presentinvention includes improved tissue anchors for enhancing anchorattachment to valve annulus tissue. Such improved anchors typicallyinclude one or more features to help prevent the anchors from pullingout of tissue, when the anchors are placed under tension from a cinchedtether, and/or to help promote tissue ingrowth of the anchors to furtherenhance attachment. In one embodiment, as shown in FIG. 16A, a tissueanchor 810 includes outwardly facing hooks 812 or bends at the ends ofthe two arms of anchor 810. In another embodiment, as in FIG. 16B, atissue anchor 820 includes inwardly facing hooks 822. In a relatedembodiment, shown in FIG. 16D, a tissue anchor 840 includes multiplebends 842. In any of these embodiments, hooks 812, 822 or bends 842 havebeen found to enhance attachment of anchors 810, 820, 840 to tissue andthus prevent anchor pullout. In another embodiment, shown in FIG. 16C,two arms of a tissue anchor 830 are attached at an attachment point 832.The attachment point 832 may be formed by any suitable technique, suchas soldering or the like. In another embodiment, as in FIG. 16E, a belt852 may be disposed over a tissue anchor 850 to hold the two arms of theanchor together. In either of the embodiments shown in FIGS. 16C and16E, holding the two arms of the anchor together has be found to reducepullout of the anchors 830, 850 from tissue.

In the embodiments just described or in alternative embodiments, tissueanchors may also have one or more features designed to enhance ingrowthand/or encapsulation of the anchors into annular tissue. Such features,for example, may include a coating, a porous and/or rough surface, anattachment such as a polyester band or belt, or any other suitablesurface feature or added feature. By promoting encapsulation of tissueanchors, attachment strength of the anchors to tissue is enhanced.

Referring now to FIGS. 17A-17C, in many embodiments, self-forminganchors 900 are stored in the delivery device in a straightenedconfiguration, coupled with a tether 902, as shown in FIG. 17A.Basically, anchors 900 are held or restrained in that straightenedstate, while their natural configuration is curved. Thus, when thestraightened anchor 900 is released from the delivery device into tissueT, the anchor 900 actually pulls itself into the tissue T, as shown inFIG. 17B, due to the storage of potential energy in the straightenedstate and the tendency of each of the arms 901 of anchors 900 to drivethe tip of the arm into the tissue as illustrated. Arms 901 are joinedtogether at a junction 903. Each arm 901 is braced against the other armso that forces exerted by tissue T on each arm 901 are opposed by theother arm 901 wherein the arms are joined to one another. Thiseliminates the need for an anchor driving device, such as required withstaples, thus substantially simplifying the assembly and method. Inaddition, bracing arms 901 against one another also helps to reduce oreliminate problems associated with tissue deflection. As shown by thehollow-tipped arrows in FIG. 17B, the anchor 900 pulls itself intotissue T as it assumes its natural, curved shape, and exerts forces invertical, horizontal and curved directions. Finally, after pullingitself into tissue and assuming its natural shape, as in FIG. 17C,anchor 900 is fully embedded in the tissue T.

In an alternative embodiment, as shown in FIG. 18, anchors 910 may haveone curved arm and one straight arm. Such an anchor 910 will still pullitself into tissue T, thus embedding itself and positioning the tether912 flush with the tissue T.

Referring now to FIG. 19A, some embodiments of a valve annulus anchordevice may include anchors 922, a tether 924, a distal force applyingmember 927 coupled with the tether 924, a termination member 926 and oneor more force distributing sleeves 920 disposed over the tether 924 andbetween adjacent anchors 922. In one embodiment, as shown, a separatesleeve 920 may be disposed between two adjacent anchors 922 a, 922 b.Additional sleeves 920 may optionally be disposed between other sets oftwo anchors, such as anchors 922 b and 922 c. In FIG. 19A, only threeanchors 922 are shown for simplicity, but any number of anchors 922 andsleeves 920 between anchors may be used in various embodiments. Sleeve920 acts to distribute force applied between two adjacent anchors 922,to help prevent such anchors 922 from pulling out of tissue when forceis applied to tether 924. Sleeve 922 may be made of any suitablematerial, such as but not limited to metals, such as Nitinol, polymers,fabrics and the like. Sleeve 922 may be a solid cylindrical member, oralternatively may have patterned cut-outs, like a stent, or be made ofribbed, woven, braided, porous, nonporous or any other suitablematerial, pattern, configuration or the like. Sleeve 920 may beessentially rigid and axially incompressible, while in other embodimentsit may be axially compressible. In one embodiment, sleeve 920 may beconfigured as two rings, disposed adjacent two anchors 922, with therings being connected by a rod or shaft, so that tether 924 is notencircled by the sleeve 922.

With reference now to FIG. 19B, in an alternative embodiment, a sleeve930 may be disposed over a tether 934 so as to extend between more thantwo anchors 932. Such a sleeve 930 may thus distribute force appliedbetween a termination member 936 and a force applying member 937 so asto help prevent anchor pull-out from tissue. Such a sleeve 930 mayinclude one or more openings through which one or more middle anchorsmay extend. Again, sleeve 930 may have any suitable configuration, size,shape or the like and be made of any suitable material or combination ofmaterials. Sleeve 930 may extend between three, four, five or anysuitable number of anchors 932 in various embodiments. In an alternativeembodiment, sleeve 930 may be pierced by one or more of the anchors 932and thus attached to valve annulus tissue.

Although the foregoing is a complete and accurate description of thepresent invention, the description provided above is for exemplarypurposes only, and variations may be made to the embodiments describedwithout departing from the scope of the invention. Thus, the abovedescription should not be construed to limit the scope of the inventionas described in the appended claims.

1-32. (canceled) 33: A method for delivering a cinchable assembly toheart tissue comprising: advancing a catheter through an aorta andbeneath a mitral valve such that the catheter is positioned along acircumferential length of tissue adjacent to the mitral valve annulus,wherein the catheter has one or more apertures positioned along alongitudinal length thereof for delivering one or more anchorstherethrough; delivering a first anchor through one of the apertures,wherein the first anchor is coupled to a tether; delivering a secondanchor through one of apertures, wherein the second anchor is coupled tothe tether; and tensioning the tether to reduce the distance between thefirst and second anchors, wherein at least one force distributing memberis positioned along the tether between the first and second anchors. 34:The method of claim 33, wherein at least one of the anchors is slidablycoupled to the tether. 35: The method of claim 33, wherein at least oneof the anchors is configured to self-secure into tissue. 36: The methodof claim 33, further comprising stabilizing the catheter along thecircumferential length of tissue adjacent to the mitral valve annulus.37: The method of claim 34, wherein the catheter is stabilized byexpanding an expandable member coupled thereto, such that the expandablemember urges the catheter against the length of tissue. 38: The methodof claim 33, wherein the force distributing member comprises a generallytubular member. 39: The method of claim 38, wherein the tether passesthrough the generally tubular member. 40: The method of claim 33,wherein the force distributing member has a textured outer surface. 41:The method of claim 33, wherein the force distributing member isnonporous. 42: The method of claim 33, wherein the force distributingmember is porous. 43: The method of claim 42, wherein the pores of theforce distributing member are formed by cutouts in the forcedistributing member. 44: The method of claim 33, wherein the forcedistributing member comprises a woven or braided material. 45: Themethod of claim 33, wherein the force distributing member reduces theresultant force applied to at least one of the first or second anchorswhen the tether is under longitudinal tension, the resultant force beingin the same direction as the pull out force of the anchor. 46: A methodfor delivering a cinchable assembly to heart tissue comprising:advancing a catheter through an aorta and beneath a mitral valve suchthat the catheter is positioned adjacent to the mitral valve annulus;and delivering an anchor assembly from the catheter, wherein the anchorassembly comprises at least two anchors positioned along an axiallyshrinkable backbone, wherein the axially shrinkable backbone is capableof transitioning from a first extended length to a second reduced lengthupon deployment of the anchor assembly. 47: The method of claim 46,wherein advancing the cathether adjacent to mitral valve tissuecomprises positioning the catheter along a circumferential length oftissue adjacent to the mitral valve annulus. 48: The method of claim 47,further comprising stabilizing the catheter along the circumferentiallength of tissue. 49: The method of claim of claim 46, wherein thebackbone comprises a shape memory material. 50: The method of claim 49,wherein the backbone comprises a nickel titanium alloy. 51: A method fordelivering a cinchable assembly to heart tissue comprising: advancing acatheter through an aorta and beneath a mitral valve such that thecatheter is positioned along a circumferential length of tissue adjacentto the mitral valve annulus; stabilizing the catheter adjacent to themitral valve annulus; delivering a first anchor from the catheter,wherein the first anchor is coupled to a tether; delivering a secondanchor from the catheter, wherein the second anchor is coupled to thetether; and tensioning the tether to reduce the distance between thefirst and second anchors, wherein at least one force distributing memberis positioned along the tether between the first and second anchors. 52:The method of claim 51, wherein the catheter is advanced adjacent to themitral valve through a guide catheter. 53: The method of claim 51,wherein stabilizing the catheter comprises urging the catheter againsttissue. 54: The method of claim 53, wherein urging the catheter againsttissue comprises urging the catheter against tissue using one or moreexpandable devices. 55: The method of claim 53, wherein urging thecatheter against tissue comprises using one or more magnet members. 56:The method of claim 51, further comprising visualizing the tissue.